Oil and water separating pump for oil wells



July 26, 1960 c. L. HOOKER, JR

OIL AND WATER SEPARATING PUMP FOR 011. WELLS Filed Nov. 7, 195'? m N T Ne e E 5 o w z T 2 I O T 0 A H G L s m E v. m B M i C u o z T G 8 II] w.m I F 5;. a w/ 4 A. "M 8 nfl 9 5 5 1 ,n,. o I -uqm m4. 3 3-!- w w 3V/uv/vv a 3 5 9 n [1: Z 1 /w Z 5 1 4 3 Al 4 2 4| 0 1/ 9 drill I I I 2 2.I z F 2,946,387 OIL AND WATER SEPARATING PUMP FOR OIL WELLS Charles L.Hooker, Jr., P.(). Box 1'5, Bradley, Fla. Filed Nov. 7, 1957, Ser. No.694,960 15 Claims. (Cl. 166-105) The present invention relates to oilwell pumps and more particularly to a pump for extracting oil from amixture of oil and water;

It is an object of the invention to provide a pump of simple and ruggedconstruction which may be installed in an oil well casing for thepurpose of pumping oil from the casing while at the same time rejectingwater which may be mixed with the oil.

It is a further object of the invention to provide a pump which will bepractical and reliable in operation for the purposes set forth and whichwill have simple and easily manufactured components.

It is a further object of the invention to provide a pump having acylinder which may be made in extreme lengths, possibly extending downinto the oil well casing for a hundred or more feet and having a pistonwith astroke commensurate with the length of the cylinder.

It is a still further object of the invention to provide a pump whichmay be constructed in extreme lengths wherein a reciprocal piston may beactuated from top to bottom of the cylinder in a simple and practicalmanner with a minimtun of moving parts.

Briefly, my invention contemplates the use of a pump.

cylinder having a reciprocal piston therein wherein the piston isreciprocated by means of a shaft having a reversing thread, wherein theshaft is rotated as by an electric motor. The piston has a pawlarrangement secured thereto which coacts with the reversing thread ofthe shaft thereby causing the piston to reciprocate as the shaftrotates. Each time the pawl reaches an end of the reversing thread atthe top or bottom of the rotary shaft the piston reverses direction.Thus, continual reciprocation of the piston is effected. Carried by thepiston at a lower surface thereof is a tube having a hollow central borecommunicating with small lateral ports in the tube sides. Thedisposition of the tube is such that as it reciprocates up and down thecylinder with the piston, the laterally ported surface remains disposedwithin approximately the lower one-third of the cylinder. .Thus,

.water mixed with the oil separates out by gravity and flows through theported side of the tube and down through the central bore and outwardlyof the pump through a discharge valve provided in a separate housingattached to the lower end of the pump cylinder. By providing a valveport through the piston the lighter component of the oil-water mixture,namely the oil, communicates through the piston to the upper surfacethereof and upon movement upwardly of the piston is lifted toward theupper end of the cylinder and ultimately out of the cylinder throughsuitably provided port means.

A detailed description of my invention will now be given in conjunctionwith the appended drawing in which:

Fig. 1 is a longitudinal section through the pump shown installed in anoil well casing, and

Fig. 2 is a section through 2-2 of Fig. 1.

Referring now to the drawing, a well casing 1 is disclosed wherein isdisposed a pump cylinder 2 supported in the well casing as by a flangedcoupling 5 to which is connected a discharge. pipe 8 suitably fastenedin any known manner to a top cover 12 of the casing. Thus, the cover 12may be welded to both the discharge pipe and the casing or threadedlyconnected thereto. Reciprocally disposed within the cylinder is a piston15 sealed as by ice piston rings 18 and having a valve passage 22 inwhich is disposed the spring-biased ball check valve 25, as shown, itbeing understood that the valve 25 opens in the upward direction whenthe piston 15 is forced downwardly.

Inasmuch as the separating action taking place within the pump cylinderdepends on the different specific gravities of the oil and the water ofa mixture drawn into the cylinder, it will, of course, be appreciatedthat the cylinder is mounted vertically or substantially vertically soas to have a lower end 30 and an upper end 33.

Rising upwardly in the cylinder is a tubular shaft 36 non-rotativelysecured to piston 15 as by a threaded stud carried at the end of shaft36, as shown, or other suitable means. The tubular shaft carries a pawl39 having a protrusion accommodated in a reversing thread 42 ofconventional shape cut into a rotary shaft 45 which shaft is coupled bya pin as shown to a nipple 48 splined as shown to a power shaft SZcarried at the upper end of the discharge pipe in suitable bearings, andhaving a pulley keyed thereto. Thus, rotation of shaft 52 effectsrotation of shaft 45 and by virtue of the pawl 39 secured to the tubularshaft 36 repetitive reciprocation of piston 15 is effected, the piston15 being restrained against rotary movement in a manner to behereinafter set forth.

Secured as by a threaded stud to the under face of the piston 15 andextending downwardly into the cylinder is a square shaft 58 whichterminates in a square ported tube 62 having a central bore 65 and aseries of small laterally disposed ports such as 68. The shaft 58reciprocates in a square bore 71 in an end closure member 74 which maybe threaded to the end of the cylinder as shown. The closure member 74is provided with a coupling extension 81 which threadedly carries anoutlet discharge means 84 at the bottom of which is secured a ball checkvalve 87 biased upwardly as by a spring so as to open to permit egressof fluid from the outlet discharge pipe 84 when suitable pressure occurstherein.

A spring-biased ball check valve 90 is carried by the closure member 74and biasedv closed in a downward direction but being operative to openon an upward suction stroke of the piston 15.

The shaft 58 is polygonal in cross section exteriorly, for example, itmay be square asshown. and co-acts with square bore 71 to preventrotation of piston 15. Thus, the piston is restrained to purereciprocation effected by rotation of the reversible thread member 45.

Thedisposition of the ports 68 is such that when the piston 15 is at thetop of its stroke as shown the ports are disposed approximately withinthe lower third of the chamber formed by closure member 74.

In operation, assuming the piston is going in an upward directioneffecting a suction stroke, the valve 90 opens while the valve 87 closesand a mixture of oil and water is drawn intothe lower portion 30 of thecylinder, valve 25 being closed at this time. During the rise time ofthe piston from its lowermost position to its uppermost position, themixture being drawn into the cylinder below the piston begins to settleout, the heavier component, that is the water, forming a strata belowthe oil. Depending upon the rise time of the piston, a certain amount ofthe water will flow through ports 68 and bore 65 down into the outletdischarge pipe 84. Upon the return or downward stroke of the piston, thevalve 25 is forced open and the lighter component of the mixture in thelower portion of the cylinder, namely the oil,

the lower face of the piston and the which has separated out at the topof the mixture, is

substantially oil-filled after a few strokes of the piston.

Upon each down stroke of the piston the mixture in the lower chamber,which is for the most part water, is forced through ports 68 and bore 65into the outlet discharge pipe 84, cracking valve 87, whence thesubstantially watery mixture is forced back into the well casing. Thevalve 90 Will be understood to be closed at this time.

After the upper portion 33 of the cylinder becomes filled with oil, theoil is forced upwardly through ports 92. provided in the closure cap 5and past a funnel-shaped guide means 93 which may be integral with theconnecting nipple 48, and ultimately out of a discharge spout 97.

It will be noted that as the piston moves downwardly the ports 68 willultimately be closed ofl by virtue of moving into the sleeve extension81 of the end cap 74. This closing of the ports 68 cuts off egress ofwater or mixture from the lower portion of the cylinder to the dischargeoutlet 84, while at the same time builds up pressure for cracking thevalve 25 so that the upper, or lighter oil strata of the fluid in thelower chamber may be forced into the upper portion 33 on each stroke.

It will, of course, be appreciated that the valve 25 is set to open atany predetermined pressure at a time subsequent to the uppermost port 68being blocked by the sleeve 81, While the spring bias on the valve 87 issuch that the valve is readily cracked upon an increase of pressure inthe discharge pipe 84 as the piston moves downwardly. Valve 87 will, ofcourse, remain open just so long as fluid is being forced into thedischarge pipe 84.

From the foregoing description of the construction it will be apparentthat the cylinder may be made extremely long. This is an importantfeature of the invention inasmuch as it requires a certain amount oftime for the heavier water component of the mixture to settle to thebottom of the lower chamber for egress through ports 68. I have foundthat it takes some twenty or thirty seconds for effecting settling. Inthis time the piston 15 is continually moving on an up stroke andaccordingly the greater the length of the cylinder the longer the upstroke in point of the time of the piston. Therefore, the speed ofrotation of the reversible thread element 45 is correlated suitably tothe length of stroke of the piston which is in turn dependent upon thelength of the cylinder so as to provide a suitable rise time for thepiston in order to eifectively permit the water to settle out of themixture. By virtue of the very simple and rugged means for reciprocatingthe piston, namely the reversing thread component, a slow piston rise isreadily effected, the pitch of the reversible threads having, of course,an eifect coupled with the speed of rotation on the rate of piston rise.

For extreme lengths of cylinder it is, of course, apparent that somereliance'on the pressure existing in the casing must be made in order toeffect ingress of the mixture into the cylinder on each up stroke of thepiston.

From the foregoing it will be apparent that the variable factors withincontrol of the designer are the pitch of thread, speed of rotation ofthe threaded shaft, and length of cylinder. By suitable choice of speedand sizes the rate of rise of the piston to atford a proper degree ofsettling of the water at the lower portion of the cylinder may bereadily arrived at for any pump required for use under practicaloperating conditions. 1

Having thus described my invention I am aware that various changes maybe made without departing from the spirit of the invention andaccordingly I do not seek to be limited to the precise illustrationherein given except as set forth in the following claims.

I claim:

1. In a pump for separating a lighter from a heavier fluid of a mixtureof said fluids, tubular means comprising a cylinder having an upper endand a lower end; an inlet valve communicating with the interior of thec'ylin der and an outlet valve at the lower end thereof; meanscomprising a reciprocating piston in said cylinder, a valved passagethrough said piston comprising a valve actuatable to open position in adownward direction of movement of said piston, and conduit meansactuated in response to piston motion and in the same direction as saidpiston and etfecting communication between the lower end of saidcylinder and said outlet valve for a predetermined portion of travel ofsaid piston in said cylinder and disposed for directing a return flow ofheavier fiuid to said outlet valve.

2. In a pump of the class described, a tubular means comprising acylinder having an inlet valve communicating with the interior thereof,and having an outlet discharge means at one end thereof; meanscomprising a reciprocating piston in said cylinder, a conduit means 1movable in response to movement of said piston and in the same directionand eifecting communication between said cylinder and said dischargemeans for a predetermined portion of travel of said piston in saidcylinder.

3. In a pump for separating a lighter from a heavier fluid of a mixtureof said fluids, a tubular means comprising a cylinder having an upperand a lower end; an inlet valve communicating with the interior of saidcylinder and an outlet valve, said valves being disposed at the lowerend of said tubular means; means comprising a reciprocating piston insaid cylinder, a valved passage means through said piston comprising avalve actuatable to open position in a downward direction of movement ofsaid piston, and ported tube conduit means actuated in response topiston motion and in the same direction and eifecting communicationbetween the lower end of said cylinder and said outlet valve for apredetermined portion of travel of said piston in said cylinder anddisposed for directing a return flow of heavier fluid to said outletvalve, wherein said cylinder is of such length as to effect a settlingchamber for a heavier fluid to separate from a lighter fluid adjacentsaid lower end.

4. In a pump of the class described, a tubular means comprising acylinder having an inlet valve communicating with the interior thereofand having a discharge means at one end; means comprising areciprocating piston in said cylinder, conduit means actuated inresponse to piston motion and in the same direction and effectingcommunication between said cylinder and said discharge passage means fora predetermined portion of travel of said piston in said cylinder,including means for reciprocating said piston comprising a rotativeshaft having a reversing thread; and means disposed at said end of saidcylinder and co-acting with said conduit means for restraining rotationof said piston, said conduit means being secured non-rotatively to saidpiston and carried thereby.

5. In a pump of the class described, a tubular means comprising acylinder having an inlet valve communicating with the interior thereofand having a discharge means at one end; means comprising areciprocating piston in said cylinder, a conduit means reciprocal withsaid piston and actuated in response to piston motion and in the samedirection and effecting communication between said cylinder and saiddischarge means for a predetermined portion of travel of said piston insaid cylinder, said conduit means being carried by said piston, saidcylinder having an end closure provided with a bore through which saidconduit means moves toward said end of said cylinder, said dischargepassage means comprising said movable conduit means and also comprisingstationary housing means disposed exter1orly of said cylinder, in whichhousing means said movable conduit means reciprocates as said pistonreciprocates, said housing means having an outlet valve for egress ofreturn fluid therethrough.

6. In a pump of the class descr1bed, tubular means comprising a cylinderhaving an inlet valve communicating with the interior thereof, andhaving discharge passage means at one end; means comprising areciprocating piston in said cylinder, a conduit means reciprocal withsaid piston and actuated in response to piston motion and in the samedirection, and. effecting communication between said cylinder and saiddischarge passage means for a predetermined portion of travel of saidpiston in said cylinder, said conduit means being carried by saidpiston, said cylinder having an end closure provided with a bore throughwhich said conduit means moves as said piston moves toward said end ofsaid cylinder, said discharge passage means comprising a portion of saidtubular means, and housing means disposed exteriorly of said cylinder,in which housing means said conduit means reciprocates as said pistonreciprocates, said discharge passage means also comprising said housmgmeans.

7. In a pump of the class described, a tubular means comprising acylinder having a discharge passage means at one end, means comprising areciprocating piston in said cylinder having an inlet valvecommunicating with the interior thereof, conduit means comprising aported tube reciprocated by said piston in response to piston motion andin the same direction, and eflecting a communication bet-ween saidcylinder and said discharge means for a predetermined portion oftravelot said piston in said cylinder, said ported tube being carried bysaid piston, said cylinder having an end closure provided with a borethrough which said tube moves as said piston moves toward said end ofsaid cylinder, said discharge passage means comprising said tube, andhousing means disposed exteriorly of said cylinder, in which housingmeans said ported tube reciprocates as said piston reciprocates, saiddischarge passage means also comprising said housing means.

8. In a pump of the class described, a tubular means comprising acylinder having an inlet valve communicating with the interior thereof,said cylinder having one end lower than the other end and a dischargepassage means at the lower end, means comprising a reciprocating pistonin said cylinder, conduit means reciprocal with said piston and actuatedin response to piston motion and in the same direction and effectingcommunication between said lower end of said cylinder and said dischargemeans for a predetermined portion of travel of said piston in saidcylinder, wherein said cylinder is of such length as to effect asettling chamber at the lower end thereof for a heavier fluid toseparate from a lighter fluid, said ported tube being connected to saidpiston and carried thereby.

9. In a pump of the class described, a tubular means comprising acylinderhaving an inlet valve communicating with the interior thereofand having an upper and a lower end and a discharge passage means at thelower end; means comprising a reciprocating piston in said cylinder,conduit means reciprocal with said piston and actuated in response topiston motion and in the same direction and effecting communicationbetween said lower end of said cylinder and said discharge means for apredetermined portion of travel of said piston in said cylinder, whereinsaid cylinder is of such length as to effect a settling chamber at thelower end thereof for a heavier fluid to separate from a lighter fluid,said conduit means being secured to said piston and carried thereby,said cylinder having an end closure provided with a bore through whichconduit means moves as said piston moves toward said lower end of saidcylinder, said discharge means comprising said conduit means; andhousing means disposed exteriorly of said cylinder, in which housingmeans said ported tube reciprocates as said piston reciprocates,including an outlet valve disposed in said housing means, said dischargemeans also comprising said housing means.

10. In a pump of the class described, tubular means comprising acylinder having an inlet valve communicating with the interior thereof,and discharge passage means atone end thereof, means comprising areciprocating piston in said cylinder, conduit means reciprocal withsaid piston and actuated in response to piston motion and in the samedirection and efiecting communication between said cylinder and saiddischarge passage means for a predetermined portion of travel of saidpiston in said cylinder, said discharge passage means comprising saidconduit means, and a valve carried by said piston and openable bypressure as said piston approaches said one end of said cylinder topermit fluid to pass through said piston as said piston approaches saidone end of said cylinder.

11. In a pump of the class described, tubular means comprising acylinder having an inlet valve communicating with the interior thereof,means comprising a reciprocating piston in said cylinder, conduit meansactuated in response to piston motion and in the same direction, saidcylinder having a closed end and a portion of said conduit meansprotruding through said closed end and reciprocally movable with respectthereto for establishing communication between the interior and theexterior of said cylinder for a predetermined portion of travel of saidpiston in said cylinder, means for reciprocating said piston toward saidclosed end whereby, as said piston approaches said closed end, fluid isforced through said conduit means out of said cylinder, said conduitmeans comprising a tubular element having a bore extending therein ofpredetermined length, said bore having a length shorter than the strokeof said piston and being open at the end of said tubular elementexteriorly of said cylinder, and laterally disposed aperture meansthrough said tubular element communicating said bore with the interiorof said cylinder for said predetermined portion of travel of said pistontoward said end of said cylinder.

12. In a .pump as set forth in claim 11, including an outlet dischargemeans exteriorly of said cylinder at said lower end thereof, saidtubular element being reciprocal with said piston so that a portion ofsaid tubular element moves to and fro Within said discharge means, saidoutlet discharge means comprising an outlet discharge valve.

13. In a pump for separating a lighter from a heavier fluid of a mixtureof said fluids, tubular means comprising a cylinder having an upper endand a lower end; an inlet valve communicating with the interior of saidcylinder and 'an outlet valve disposed at the lower end thereof; meanscomprising a reciprocating piston in said cylinder, a valve passagethrough said piston comprising a valve actuatable to open position indownward direction of movement of said piston, and flow conducting meansactuated in response to piston motion and in the same direction thereof,and efiecting communication between the lower end of said cylinder andsaid outlet valve during a downward motion of said piston for directingreturn flow of a heavier fluid to said outlet valve for a predeterminedlength of travel of said piston in said cylinder.

14. In a pump as set forth in claim 13, said conducting means comprisinga rod-like member having a hollowed portion for effecting saidcommunication.

15. In a pump as set forth in claim 14, a discharge pipe disposed at thelower end of said cylinder, said outlet valve being disposed within saiddischarge pipe, said rod like member extending into said discharge pipeto eflect communication between said lower end of said cylinder and saidoutlet valve for said predetermined portion of travel of said piston.

References Cited in the file of this patent UNITED STATES PATENTS1,104,962 Clark July 28, 1914 1,649,524 Hammond Nov. 15, 1927 2,022,859Herbsman et a1. Dec. 3, 1935 2,214,064 Niles Sept. 10, 1940 2,296,164Humphrey Sept. 15, 1942 2,523,091 Bruce Sept. 19, 1950 2,692,051 WebbOct. 19, 1954 2,762,437 Egan et a1. Sept. 11, 1956 2,817,298 BloudoflDec. 24, 1957

